Alcoholate and method of making same



Patented Feb. 24, 1931 PATENT OFFICE FELTX KAUFLER AND H. GEORG STANGLER, F MUNICH, GERMANY, ASSIGNORS TO ALEXANDER WAGKE'R GFSELLSGHAFT FUR ELECTROGHEMISCHE INDUSTRIE, OF

MUNICH, GERMANY ALQOEOLA TE AND METHOD OF MAKING SAME Ho Drawing. Application filed April 24, 1930, Serial No. 447,094, and in Germany June 13, 1829.

This invention relates to a process of preparing alcoholates and more particularl to aluminum alcoholates contaimng metal a1- -ides. It is necessary that aluminum alcohol- 5 ates which are to be used for certain purposes, contain a few percent of a metal halide. This is particularly true where the alcoholate is being used as a catalyst or quasi catalyst in various chemical processes such as in the preparation of ethyl acetate by passing acetaldehyde into a solution of aluminum alcoholate in a solvent having a higher boilinglpoint than acetaldehyde.

eretofore aluminum alcoholates contain-' ing metal halides have been made by using a preformed metal halide, either by reactin aluminum, alcohol, and a metal halide suc as aluminum chloride or mercury chloride, or adding the metal halide after formation 80 bf the aluminum alcoholate. These alcoholates have-also been made, by reacting aluminum, alcohol, and iodine. All of these methods are unsatisfactory due to the high cost of the preformed metal halides or iodine.

The use of chlorine, most available and cheapest of the halogens, to supply the halogen for the formation of the metal halide in situ in these compositions has heretofore been considered impractical since it is well known that chlorine will attack alcohol and, also,

that aluminum chloride accelerates the chlorination of organic compounds. Likewise, it is known that very considerable amounts of ethyl chloride are formed by the use of anhydrous hydrochloric acid in the presence of aluminum chloride in alcohol solution. Bromine, possessing properties very similar to chlorine, has also not been used for this purpose for the same reasons.

40 An object of the present invention is to provide a rocess in which the metal halide can be ma e readily in situ without formation of wasteful and injurious by-products. We have now made the unexpected discovery that aluminum alcoholate with the desired content of metal halide can be obtained by treatin a mixture of aluminum and alc6- hol with c lorine or bromine in the presence of an indifferent solvent.

Contrary to the known behavior of these halogens in the presence of organic compounds, in this process they do not combine with the alcohol to form various halogen sub stitution products, as would be expected, but

combine with the aluminum to form aluminum halide, causing the aluminum to rapidly go into solution.

If it is desired to obtain an alcohol free aluminum alcoholate solution, the process may be carried out in the presence of an excess of aluminum or an excess of aluminum may be added during the course of the reaction.

By this process aluminum alcoholates can be obtained having an aluminum chloride or bromide content up to 50% by weight of the aluminum alcoholates although an aluminum halide content up to 15% is sufficient for most purposes.

Ethyl alcohol or its homologues, methyl, propyl, butyl alcohol, etc., may be used as the alcohol in this process. The halogen may be supplied as chlorine gas or chlorine compounds which will ive up their chlorine to aluminum such as hy rochloric acid, cupric chloride, hypochlorous acid, chloramine, or as bromine or analogous bromine compounds.

Ethyl acetate is preferred as the indifferent solvent but the following solvents may also be mentioned: methyl acetate, butyl acetate, benzol, toluol, xylol, liquid benzine hydrocarbons.

The product resulting from this process, i. e., an aluminum alcoholate containing an aluminum halide, can be used in many chemical reactions. It is especially effective as a catalyst for the conversion of acetaldehyde .to ethyl acetate.

Examples 1. Dry chlorine gas was introduced into a mixture of 200 gms. of dry ethyl acetate and 105 gms. of absolute alcohol containing 25 gms. of aluminum shavings at the boiling point of said mixture (about 7 0 C.) at such rate that 6 gms. of chlorine were used up after eight hours in the formation aluminum chloride. The resulting product was aluminum ethylate containing aluminum chloride alcoholates containing an aluminum halide with only traces of chlorine substitution products.

2. 105 gms. of absolute alcohol containing 12 gms. of hydrogen chloride were gradually introduced into a mixture of 25 gms. aluminum and 200 gms. ethyl acetate at a temperature of about 7 278 C. After several hours about 80% of the aluminum had gone into solution giving aluminum ethylate containing aluminum chloride with only the slightest traces of chlorine substitution products.

3. 10 grams of aluminum in granular form were covered with 46 grams of absolute alcohol and 200 grams ethyl acetate and 5 grams of bromine were gradually added to the mixture during 2 hours with stirring. After 3 hours all the aluminum had gone into solution to form aluminum ethylate which contained about 10% of its weight of aluminum bromide.

This process may be carried out at a temperature of 40 G.-to 160. C. but the preferred I range is 60 C. to C.

In the foregoing examples, the aluminum alcoholate containing aluminum chloride or bromide is obtained in solution. The product may be readily obtained in pure crystalline form by distilling off the solvent, preferably under reduced pressure.

The invention claimed is:

1. Process for the production of aluminum comprising treating a mixture of aluminum, an aliphatic alcohol, and an indifierent solvent with an agent selected from the group comprising chlorine, bromine, and chlorine and bromine compounds adapted to give up their halogen content to the aluminum.

, 2. Process for the production of aluminum alcoholates containing an aluminum halide oomprising'treating a mixture of aluminum, an aliphatic alcohol, and an indifferent sol vent at a temperature of 40-160 G. with an agent selected from the group comprising chlorine, bromine, and chlorine and bromine compounds adapted to give up their halogen content to the aluminum.

3. Process for the production of aluminum alcoholatescontaining an aluminum halide comprising treating a mixture of aluminum, an aliphatic alcohol, and an indifferent solvent at a temperature of 60-7 5 C. with an agent selected from the group comprisingchlorine,'bromine, and chlorine and bromine compounds adapted to give uptheir halogen content to the aluminum.

4. Process for the production of aluminum alcoholates containingan aluminum halide comprising treating a mixture of aluminum, an aliphatic alcohol, and ethyl acetate at a temperature of 40160 G. with an agent selected from the group comprising chlorine, bromine, and chlorine and bromine compounds adapted to give up their halogen content to the aluminum.

5. Process for the production of aluminum ethyla'te containing an aluminum halide comprising treating a mixture of aluminum, ethyl alcohol, and an indifferent solvent at a temperature of 40l60 C. with an agent selected from the group comprising chlorine, bromine, and chlorine and bromine compounds adapted" to give up their halogen content to the aluminum.

6. Process for the production of aluminum ethylate containing an aluminum halide comprising treating a mixture of aluminum, ethyl alcohol, and ethyl acetate at a temperature of 40160 C. with an a 6. selected from the group comprising e .lorine, bromine, and chlorine and brominecompounds adapted to give their halogen content to the aluminum.

7. Process for the production of aluminum alcoholates containing aluminum chloride comprising treating a mixture of aluminum, an aliphatic alcohol, and an indifierent solvent at a temperature of 40 C. to 160 (Lwith chlorine or a chlorine compound adapted to give up its chlorine content to the aluminum.

8. Process for the production of aluminum alcoholates containing aluminum chloride comprising treatin a mixture of aluminum,

' an aliphatlc alcoho and ethyl acetate at an elevated temperature with chlorine or a chlorine compound adapted to give upits chlorine content to the aluminum.

9. Process for the production of aluminum ethylate containing aluminum chloride comprising treating a mixture of aluminum,

ethyl alcohol, and an indifferent solvent at an elevated temperature with chlorine or-a chlorine compound adapted togive up its chlorine content to the aluminum.

'10. Process for the production of aluminum ethylate containing aluminum chloride comprising treating a mixture of aluminum, ethyl alcohol, and ethyl acetate at a temperature from 40 G. to 160C. with chlorine or a-chlorine compound adapted to give up its chlorine content to the aluminum.

. 11. Process ior the production of aluminum ethylate containing aluminum chloride comprising slowly passing chlorine intoa mixture of aluminum, ethyl alcohol, and ethyl acetate at a temperature of approxi- 12. Process for the production num ethylate containing aluminum chloride comprising slowly adding ethyl alcohol conof alumitaining'; hydrogen chloride to a mixture of aluminum and ethyl acetate: at a'temperature of approximately 60-7 5": C.

.13. Process for the preparation of aluminum 'alcoholates containing aluminum bromide comprising treating a mixture'of aluminum, an aliphatic alcohol, and an'indifierent'solvent at a temperature of 40160 C. with .bromine or a bromine compound adapted to give up its bromine content to the aluminum.

14. Process for the preparation of aluminum alcoholates containing aluminum bromide comprising treatin a mixture of alumi- 0 this twelfth day of num, ethyl alcohol, an ethyl acetate at a temperature of 40160 G. with bromineor a bromine compound ada ted to give up its I bromine content to the a Signed at Munich-Bavaria-(Germany) .xlpl'il A. D. 1930. DR. FELI KAUFLER. I DR. H. GEORG STANGLER. 

